Calling SFContentBlockerManager.reloadContentBlocker from related App extension intermittently fails

I have an app which has at least two extensions:

1. A Content Blocker extension with a request handler that returns an appropriate NSExtensionItem as part of beginRequest. A different file URL is returned depending upon if the content blocking is on or off by a user setting
2. A Safari Web Extension that includes a toolbar button and popover that enables users to enable or disable the ad blocking of the content blocker extension

All three targets (App, Content Blocker appex and Web Extension appex) use an App Group default to read and set the on or off status of the content blocking.

When the user changes the content blocking status, the app group default is updated and SFContentBlockerManager.reloadContentBlocker(...) is called.

The Content Blocker extension reads the default and then returns the appropriate file URL.

The issue is, I have noticed that whenever SFContentBlockerManager.reloadContentBlocker(...) is called from the app, Safari always applies the correct rules from the returned file URL.

However sometimes when SFContentBlockerManager.reloadContentBlocker(...) is called from the Safari Web Extension using native messaging, Safari does NOT apply the correct rules from the returned file URL.

Using logging I have confirmed that the Content Blocker extension always returns the appropriate file URL irrespective if called as a result of the app or the web extension.

Despite this, Safari does not seem to always apply the returned file URL rules when it is called from the Safari Web Extension appex. In these cases, quitting Safari and relaunching it seems to make it apply the rules correctly (obviously this is applying it due to its launch state, not due to the Web extension appex asking it to do so at that point).

All targets have access to the App Group location where the active content blocking file URL belongs and the inactive content blocking file URL is within the Safari content blocker target as a resource.

I don't think this is a memory status issue as I cannot see the Content Blocker extension being killed when it returns complex rules --- the fact it always works when called via the app also seems to rule this possibility out.

This brings up a number of questions:

1. Is calling SFContentBlockerManager.reloadContentBlocker(...) from a different appex, of the same app target and app group supported? (it seems to work sometimes and did work in previous versions of the app).
2. Is there an issue that the Content Blocker extension sometimes returns a file URL that perhaps the calling Web Extension appex may not have access to (even though Safari should via the Content Blocker extension)?
3. Any other ideas of why this may not be working correctly?
4. Has anyone else experienced this?

It seems to happen on both iOS and macOS Safari using the same codebase.